The domain is the limits of the function. Since time doesnt go negative, start with 0. At time 0, the height is 
-16(0)^2 + 144 = 144ft
Then, solve for t to find the upper limit for t, which is when the height is zero (since you're dropping the object). 
-16t^2 + 144 = 0
-16t^2 = -144
t^2 = 9
t = sqrt(9)
t = 3
The domain is 0 to 3 seconds.
        
             
        
        
        
Answer: 72 gallons
Step-by-step explanation: I added 5 and 3 then multiplied by 9.
 
        
                    
             
        
        
        
15y - 9 <36.
Add 9 to each side.
15y- 9 (+9) < 36 + 9.
15y < 45.
y < 3.
Hope it helps! :)
        
                    
             
        
        
        
Hope you could understand.
If you have any query, feel free to ask.